Rubber-joint-making instrument.



W. H. WBLCH. RUBBER JOINT MAKING INSTRUMENT.

APPLICATION IIL Patented Nov. 14, 1911.

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APPLICATION FILED IEB.2, 1907.

Patented Nov. 14, 1911.

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1,009,002, Patented NOV. 14, 1911.

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WALTER HENRY WELGI-I, OF LONDON, ENGLAND, ASSIGNOR TO HARVEY FROST &COMPANY, LIMITED, OF LONDON, ENGLAND.

RUBBER-JOINT-MAKING- INSTRUMENT.

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To all whom it may concern:

Be it known that I, WALTER HENRY WELCH, a subject of the King ofEngland, residing at London, in England, have invented certain new anduseful Improvements in RubberJoint-Making Instruments, of which thefollowing is a. specification, reference being had therein to theaccompanying drawings, forming a part thereof.

This invention relates to instruments used for making the joints inrubber tubes, especially those used in jointing pneumatic tires, thegeneral object being to secure an instrument by which to make asatisfactory joint of the two ends of the tire tube whereby the tube ismade into a hollow annulus. The joint maybe secured in any desiredmanner, as by solutioning or vulcanizing, but vulcanizing is thepreferable course. Hitherto when vulcanizing a joint of this kind, greatdifficulty has been experienced in making the two surfacesadheresatisfactorily during the vulcanizing process on account of thedifficulty of obtaining satisfactory pressure inside the mold.

Therefore, a more particular object of my invention is to providesuitable means for producing such internal pressure.

Other objects and advantages of my in vention will hereinafter appear.

In carrying out the present invention the necessary internal pressure isprovided by means of an instrument which may be termed an expandingmandrel.

My invention includes such a mandrel in which there is left through thecenter of the mandrel an unobstructed passageway for' the tire tube (oneend of which is folded back over the outside of the mandrel. for

jointing to the other end of the tire tube) and my invention furtherincludes a construction permitting the removal of the mandrel from theclosed hollow annulus of the tire tube.

My invention also includes an expanding mechanism for the mandrel.

My invention also includes several fea tures of construction andcombinations of parts, as will appear from the following description.

The instrument may comprise a length of mandrel tube, more or lessapproximately equal to the length of the joint. This mandrel tube issplit or divided longitudinally at one side and expanding means for theSpecification of Letters Patent.

Application filed February 2, 1907.

Patented Nov. 14, 1911. Serial No. 355,447.

mandrel tube are provided and are laterallydisposed with relationthereto so as to leave unobstructed the central aperture therein,

mandrel tube, which are usually more or less spaced to provide room forthe expanding mechanism.

In order to prevent deleterious effect upon or injuries to the rubbertube because of the comparatively large space or gap between the edgeswhere the mandrel tube is split or divided, I prefer to inclose theexpanding mandrel tube in another similar mandrel tube which is merelydivided or split longitudinally so that the edges come close together.By this means when the inner mandrel tube is expanded the outer one isalso expanded, but does not present the large and more or less irregularopening of the internal one, and being comparatively thin, forms, withthe internal tube, a substantially outwardly smooth lap joint. In usingthis instrument the two ends of the rubber tube to be joined are broughttogether and placed one over the other in the usual manner with thenecessary vulcanizing solution or other materials between them, theinner end of the tube being doubled a second time, thereby leaving anannular space in which the expanding apparatus is placed, the gaps inthe two parts readily permitting both mandrel tubes to be placed on therubber tire tube or removed therefrom after the joint is completed; or,if preferred, the expanding mandrel may be first placed upon one end ofthe rubber tube and the latter doubled over afterward. In order tovulcanize the joint, I prefer to employ a divided mold, steam heated orotherwise heated. This mold can be placed upon the joint and by means ofthe expander or mandrel, the two faces of the joint can be pressedfirmly against the mold and the necessary pressure thus obtained. henthe vulcanization is completed, the divided mold can be removed and theexpander or mandrel also removed by taking it apart and passing therubber through the gaps formed at the longitudinal divisions or splitsin the mandrel tubes.

I shall now describe the several instruments illustrated in theaccompanying drawings and embodying my invention and shall thereafterpoint out my invention in claims.

Figure 1 is a perspective view of one form of mandrel. Fig. 2 shows inperspective another construction with the parts separated. Fig. 3 is aperspective view of the mandrel shown in Fig. 2 with the parts in theiroperative position and a rubber tire tube in place, portions beingbroken away for clearness of illustration. Fig. at is a partialtransverse section through the mandrel and tire tube shown in Fig. 3.Fig. 5 is a partial longitudinal section of the same. Fig. 6 is aperspective view of another modified construction of mandrel. Fig. 7illustrates a convenient form of outer support or mold for use with themandrel.

Like letters indicate like parts throughout the drawings, which forconvenience of description will be referred to consecutively.

\Vith reference first to Fig. 1, there is provided a non-continuousannular expansible member shown as a mandrel tube A split at A toprovide a gap and having its edges divergently separated to form awedgeshaped opening. The mandrel tube A is shown as cut away at A toaccommodate a lug B secured to another non-continuous annular expansiblemember shown as an outer mandrel tube B which encircles the innermandrel tube A and is split at B to provide a gap shown as diametricallyopposite to the gap A in the inner mandrel tube A. The lug B forms abearing for a screw-threaded rod O, the threaded portion of whichengages with a tapped lug D attached to a wedge D and forming atraveling nut. This wedge D is arranged to work in the angular opening Ain the inner mandrel tube A, the adjacent edges of which are shown asturned inward to form wedging surfaces; and rotation of the screw O bymeans of its handle C will cause the wedge D to move relatively to theopening and to expand the inner tube A or allow it to contract, byreason of its own resiliency, according to the direction of the movementof the wedge. The expansion of the mandrel tube A necessarily bringsabout the expansion of the encircling outer mandrel tube B. It should benoted that the lug B acts as a stop or abutment to prevent the innermandrel tube A from moving longitudinally relatively to the tube Bduring the expanding operation.

In the form of construction shown in Figs. 2 to 5, inclusive, and towhich the claims are more particularly directed, the expansion of theinner mandrel tube A is brought about by means of toggle links E insteadof the wedge D. These toggles are pivotally attached to a rod O and areprovided with pins E which removably fit into holes A in the inner tubeA. In this construction the same outer split mandrel tube B may be andis shown as employed as in the construction described with reference toFig. 1, and having the lug B through which a projecting screw-threadedportion of the rod O freely passes and is operable by means of a wingnut C to thereby actuate the toggles E. Figs. 3, A and 5 show this formof the mandrel in its operative position. One end F of the pneumatictube to be jointed is first passed through the man drel and doubled overupon itself, as shown in Fig. 5. Over this doubled-over portion theother tube end F is then placed and is surrounded by a suitable outersupport, a portion of which is shown at G. This support when the jointis to be vulcanized may conveniently be of the construction illustratedby way of example in Fig. 7 where G indicates a removable linercentrally placed within a divided mold G This mold can be heated bymeans of steam or otherwise as may be desired. When the joint is placedin position within the mold or other outer support with the mandrel inoperative position, the expanding mechanism, such as the screw-threadedrod C and toggle links E, is brought into action and the mandrel formedby the mandrel tubes A and B is expanded, producing an even pressurefrom within. It will be understood that any suitable compound is placedbetween the surfaces to be jointed in the usual way. WVhen the joint hasbeen made, the mandrel is allowed to contract, as it will do by reasonof its resiliency when the nut O is loosened (or the screw C, as thecase may be), and the tube is then undoubled leaving the joint, if madein the manner described, as the usual lapped joint. The jointedpneumatic tube is removed from the mandrel through the gaps in themandrel tubes.

In the further modified construction of tool shown in Fig. 6, theexpansion of a sin gle mandrel tube A is brought about by means of along pinion H meshing with an internally toothed curved rack J. Thepinion H has smooth reduced end portions shown as carried in suitablebearings on the tube A one of these ends projecting beyond its bearings,as shown, and being provided with a pinionactuating handlewheel H Theadjacent end of the rack J is arranged to push against a suitableabutment on the mandrel tube A shown as aturned down edge A of suchtube, so that when the pinion H is rotated in the proper direction themovement of the rack J expands the mandrel tube A which is retained inits expanded condition by means of a ratchet K and pawl K carriedrespectively by the pinion H and one of its bearing lugs. On the releaseof this ratchet mechanism the mandrel tube A will. by reason of itsresiliency, resume its original contracted condition. In other respectsthan above noted,

the operation of this particular mandrel is similar to that of thosehereinbefore de scribed with reference to the other figures of thedrawings. In this construction, like those previously described, anouter expansible mandrel tube may be employed, if desired, but insteadthereof a shield L is shown as provided to bridge the gap in the mandreltube A and this shield should have a free sliding engagement with atleast one extremity of the mandrel tube A but if desired forconvenience, may be attached to the other mandrel extremity, by hingingor otherwise. The shield L prevents injury to the rubber tube, similarlyto the outer mandrel tube B, hereinbefore described.

It is understood that these various constructions of mandrels are shownand described by way of examples, and that, as broadly claimed herein,the expansion of the non-continuous tubes may be brought about by anysuitable means answering the requirement of leaving unobstructed thecentral aperture in the mandrel, to permit the pneumatic tube to passthrough the mandrel.

Although the mandrel has been described as used for making a lappedjoint, it will be seen that it is also particularly suitable for makinga flush joint when required to do so, as the pressure produced by themandrel is exerted evenly all around from within the joint.

It is obvious that various modifications may be made in theconstructions, shown in the drawings and above particularly describedwithin the principle and scope of my invention.

I claim:

1. An instrument for making joints in rubber tubes comprising anon-continuous annular expansible member which may be inserted in theannular space within the ends of the tube to exert outward pressure onthe joint and removed from said space and from the tube when the jointis completed, and expanding means for said annular memberlaterally-disposed with relation thereto so as to leave unobstructed thecentral aperture therein.

2. An instrument for making joints in rubber tub-es comprising anon-continuous annular expansible member which may be inserted in theannular space within the ends of the tube to exert outward pressure onthe joint and removed from said space and from the tube when the jointis completed, and expanding means for said annular memberlaterally-disposed with relation thereto so as to leave unobstructed thecentral aperture therein, such means including a rotative manuallyactuatable handle part located at the end of said annular member.

3. An instrument for making joints in rubber tubes comprising anon-continuous annular expansible member which may be inserted in theannular space within the ends of the tube to exert outward pressure onthe joint and removed from said space and from the tube when the jointis completed, and expanding means for said a11- nular memberlaterally-disposed with. relation thereto so as to leave unobstructedthe central aperture therein, such means including a toggle cooperativewith such member, and means for actuating the toggle.

4:. An instrument for making joints in rubber tubes comprising anon-continuous annular expansible member which may be inserted in theannular space within the ends of the tube to exert outward pressure onthe joint and removed from said space and from the tube when the jointis completed, and expanding means for said annular memberlaterally-disposed with relation thereto so as to leave unobstructed thecentral aperture therein, such means including a spreading device, andmeans for actuating such device.

5. An instrument for making joints in rubber tubes comprising anon-continuous annular expansible member which may be inserted in theannular space within the ends of the tube to exert outward pressure onthe joint and removed from said space and from the tube when the jointis completed, and expanding means for said annular memberlaterally-disposed with relation thereto so as to leave unobstructed thecentral aperture therein, such means including a spreading device, and ascrew for actuating such device.

6. An instrument for making joints in rubber tubes comprising anon-continuous annular expansible member which may be inserted in theannular space within the ends of the tube to exert outward pressure onthe joint and removed from said space and from the tube when the jointis completed, and expanding means for said annular memberlaterally-disposed with relation thereto so as to leave unobstructed thecentral aperture therein, such means including a combined screw andtoggle mechanism.

7 An instrument for making joints in rubber tubes comprising, incombination, an inner expansible split annulus, an. outer expansiblesplit annulus circumferentially surrounding the inner annulus, theannuli being adapted to be arranged so that each covers the split in theother, and expanding means for the inner annulus.

8. An instrument for making joints in rubber tubes comprising, incombination, an inner expansible split annulus, an outer expansiblesplit annulus circumferentially surrounding the inner annulus, theannuli being adapted to be arranged so that each covers the split in theother, and expanding means for the inner annulus, such means including acombined screw and toggle mechanism.

9. An instrument for making joints in rubber tubes comprising, incombination, an inner expansible split annulus, an outer expansiblesplit annulus circumfercntially surrounding the inner annulus, theannuli being adapted to be arranged so that each covers the split in theother, and expanding means for the inner annulus, such means including aplurality of toggles bridging the gap at the split in the inner annulus,and a screwthreaded actuating rod for the toggles.

10. An instrument for making joints in rubber tubes comprising, incombination, an inner expansible split annulus, an outer eX pansiblesplit annulus circumferentially surrounding the inner annulus, theannuli being adapted to be arranged so that each covers the split in theother, and expanding means for the inner annulus, such means including atoggle bridging the gap at the split in the inner annulus, alongitudinally-movable actuating rod for the toggle, and actuating meansfor such rod.

In testimony whereof I have signed my name to this specification in thepresence of tWo subscribing Witnesses.

WALTER HENRY WELCH.

WVitnesses:

RICH. CAsTLn, E. M. TOLERTON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

